View source for Video-Editing-using-Blender/C2/Build-Proxy-for-Video-Editing/English

{| border=1 
|  | '''Visual Cue'''
|  | '''Narration'''

|-
|  | '''Slide Number 1'''

'''Title Slide '''
|  | Welcome to the tutorial on '''Build Proxy for Video Editing'''

|-
|  | '''Slide Number 2'''

'''Learning Objectives'''
|  | In this tutorial, we will learn about,
* High definition video
* About time lag in playing the video
* Why a proxy is needed
* Building a Proxy and settings
* Changing memory cache size

|-
|  | '''Slide Number 3'''

'''System and Software Requirement'''
|  | To record this tutorial, I am using

* '''Ubuntu Linux''' v18.04 OS and 
* '''Blender''' 2.90.1

|-
|  | '''Slide Number 4'''

'''Pre-requisites'''

'''https://www.spoken-tutorial.org'''
|  | To follow this tutorial, 
* Learner must be familiar with the '''Blender''' interface.
* For pre-requisite tutorials, please visit this site.

|-
|  | '''Slide Number 5'''

'''Code Files'''
|  | 
* Files used in this tutorial are provided in the '''Code files''' link.
* Please download and extract the files.
* Make a copy and then use them while practising.

|-
|  | Show opened '''blender''' interface.
|  | I have already opened the '''blender''' interface in '''Video editing''' mode.

|-
|  | Go to the '''Videos''' folder in the '''File browser'''.
|  | Go to the '''Videos''' folder in the '''File browser'''.

|-
|  | Add '''proxy.webm''' in the '''Sequencer panel'''.
|  | I have saved the input file, '''proxy.webm''' in the '''Videos''' folder.

Let’s add it to the '''Sequencer panel'''.

|-
|  | '''Slide Number 6'''

'''Download Link'''

[https://commons.wikimedia.org/wiki/File:Birds_in_the_backyard_58.webm https://commons.wikimedia.org/wiki/File:Birds_in_the_backyard_58.webm] '''
|  | * The input file was downloaded from the wikimedia website as shown here.

|-
|  | Zoom out in the '''Sequencer''' panel.
|  | Let’s zoom out the video in the '''Sequencer''' panel.

|-
|  | Point to the lighter shaded region in the '''Sequencer''' panel.
|  | Notice the playback range is seen in a lighter shade.


It is from 0 to 250 frames only.
|-
|  | Highlight the frame numbers in the '''Timeline editor header'''.
|  | They are displayed in the '''Timeline editor header'''.

The video is much longer.

|-
|  | Cursor on the '''Sequencer panel'''.
|  | Let’s change the playback range to play all the frames in the video.

|-
|  | Adjust the zoom and scroll the field of view.
|  | Adjust the zoom and scroll the field of view to your convenience. 

|-
|  | Adjust the zoom and scroll the field of view.
|  | Move the playhead to the end of the video to check the frame number.

|-
|  | Cursor at the current frame number.
|  | Frame number at the playhead is also displayed in the '''Timeline editor header'''.

Note this number.

|-
|  | Change end of playback to 2700.
|  | Double click on the right most form in the header, which reads 250.

I will change it to 2700, to include the full video for playback.

|-
|  | Scroll from 2700 to 0 frames to show change in playback region.
|  | The lightly shaded region, which indicates the playback range moves to 2700.

Now the whole video will get played.

|-
|  | Select the audio clip and uncheck the box against the file name.
|  | Select the audio clip. 

For clarity in narration, I will mute the audio now, as seen here.

|-
|  | Cursor on the '''Source resolution''' in '''Strip''' tab.
|  | Notice the high resolution of the input video.

Pause this video and play the input file which is in high definition.

|-
|  | Zoom out the video in the '''Preview''' panel.
|  | Let’s zoom out the video in the '''Preview''' panel.

|-
|  | Play the video for few seconds.
|  | Let’s play the video around the one minute region. 

The video lags and is not smoothly played.

We can also move the Playhead over the region to see the lag in preview.

|-
|  | Cursor on '''Preview''' panel.
|  | Notice that, the displayed '''fps''' varies as the video is played.

|-
|  | Stop playing the video.
|  | The computer could be slow or the video is of a larger size.

Let’s stop playing the video.

|-
|  | '''Slide Number 7'''

'''Building a Proxy'''
|  | When working with HD videos,

* Creating a proxy setting is very important in video editing.
* It is to be done before starting to edit the videos.

|-
|  | Select the video strip. 

In the '''Preview''' panel, click on '''View, Proxy, Setup'''.
|  | Select the video strip. 

In the '''Preview''' panel, click on '''View, Proxy, '''and then '''Setup'''.

A small window opens.

|-
|  | Check the box for 25% and click on '''Ok'''.
|  | Notice that, proxy is not set up currently.

I will check the box for 25% and click on '''Ok'''.

|-
|  | Cursor in '''Preview''' panel.
|  | This means that, the resolution of the output will be less and hence grainy.

Finer details in the video may not be discernible in the proxy.

|-
|  | Click on '''Sidebar''', '''Proxy & cache''' tab and scroll down.
|  | Go to the '''Sidebar''' in the '''Sequencer panel'''.


'''Proxy''' setting can be accessed through the '''Proxy & cache''' tab in the '''Sidebar'''.

|-
|  | Click, hold and drag on the left edge of '''Sidebar''' to resize.
|  | I will make the panel a bit larger for clarity, as seen here.

|-
|  | Scroll down to '''Proxy Settings''' section.

Click twice on the arrow on the left.
|  | Scroll down to the '''Proxy Settings''' section.

If you do not see the options, click on the arrow to the left to show them.

|-
|  | Click on the '''Storage''' option.
|  | Click on the '''Storage''' option.

'''Proxy''' can be set for a single strip or for the project.

|-
|  | Cursor next to '''Strip proxy and timecode'''.
|  | Scroll down and notice the options under '''Strip proxy and timecode'''.

|-
|  | Check the box to define '''Directory''' for '''Custom proxy'''.
|  | Let’s check the box to define '''Directory''' for saving the '''Custom proxy''' files.

|-
|  | Click on the folder icon on the right of the form.
|  | A new form with directory name appears.

Click on the folder icon on the right of the form to open a dialogue box.

|-
|  | Select the '''Videos''' folder.

Click on '''Cancel'''.
|  | Select the '''Videos''' folder as seen here.

Now I will not change it.

Click on '''Cancel''' to keep the default.

|-
|  | Type '''Proxy''' for the new file name.
|  | If we don’t create a separate folder, '''Blender''' will create one.

A '''BL_proxy''' folder is created by '''Blender''', in the same folder as the video file.

|-
|  | Uncheck the box for Directory selection.
|  | I will uncheck the box for Directory selection for now.

|-
|  | Click the check box for '''File''' twice.
|  | The '''File''' option allows you to read in existing '''proxy''' file settings.

Now I will not change it.

|-
|  | For '''Resolution''', click on 25%.
|  | For '''Resolution''', click on 25% to choose it.

|-
|  | Check the box for '''Overwrite'''.
|  | I will also check the box for '''Overwrite'''.

|-
|  | Change value for''' Build JPEG quality''' to 30.
|  | I will change the value for '''Build Jpeg quality''', to 30.

Enter the value in the form or click hold and move the mouse on the form.

|-
|  | Scroll up in the tab.
|  | Let’s scroll up in the tab.

|-
|  | Click on '''Rebuild Proxy and Timecode indices'''.
|  | Click on '''Rebuild Proxy and Timecode indices'''.

|-
|  | Cursor on the progress bar in the right corner on building proxies.
|  | A progress bar is seen in the right corner, on '''Building proxies'''.

Allow the process to be completed.

|-
|  | '''Slide Number 8'''

'''Matched Settings'''
|  | Proxies with matching resolution must be set in
* Proxy setting in the '''Proxy and Cache''' panel and
* In the '''Preview''' panel

|-
|  | Click on '''View, Proxy''' and choose '''Set window size'''.
|  | Click on '''View, Proxy''' and choose '''Scene render size'''.

|-
|  | From the submenu, choose '''Proxy size 25%'''.
|  | From the submenu, I will choose '''Proxy size''' as '''25%'''.

|-
|  | Play the video for few seconds.
|  | Now play the video.

Notice the fps shows as 25 and the video plays smoothly without lag.

The video is now more pixelated and finer details are missing at 25% resolution.

|-
|  | Stop playing the video.
|  | Let’s stop playing the video.

|-
|  | Stop playing the video.
|  | We may be able to increase the size of cache memory which '''Blender''' can use.

This process also decreases the lag.

Let’s stop playing the video.

|-
|  | Click on '''Edit, Preferences'''.
|  | Click on '''Edit, Preferences''' to open the '''Blender Preferences''' window.

|-
|  | Click on the '''System''' tab.
|  | Click on the '''System''' tab on the left.

|-
|  | Cursor on the '''Memory Cache Limit'''.
|  | Notice that, my '''Memory Cache Limit''' is already at 4MB.

It could be different for you.

|-
|  | Close the '''Blender Preferences'''.
|  | If your hardware permits, you may increase this with caution.

Mine is at it’s limit and I will not change it.

Close the '''Blender Preferences''' Window.

|-
|  | 
|  | Pause the video, explore more options and familiarize '''proxy''' setting.

|-
|  | Show screenshot of the files in proxy directory.
|  | You may explore the low resolution video files '''Blender''' has created.

|-
|  | Cursor on the '''Blender''' interface.
|  | Make the desired edits, after setting the '''proxy'''.

When final rendering is done, the proxy will not be used.

|-
|  | Press '''Ctrl+S'''.

Then Press '''Ctrl+Q'''.
|  | You may, save the project and quit '''Blender'''.

|-
|  | '''Slide Number 9'''

'''Summary'''
|  | Now let's summarize. In this tutorial, we learned about,
* High definition video
* Time lag in playing the video
* Parameters for proxy settings
* Created low resolution videos of the starting video
* Learned about memory cache size

|-
|  | '''Slide Number 10'''

'''Assignment'''
|  | For assignment activity, please do the following.

* Practice to build proxies with different resolution.
* Explore the lower resolution output video which was created.

|-
|  | '''Slide Number 11'''

'''Assignment'''
|  | * You may also use a video of your choice to create proxy.

|-
|  | '''Slide Number 12'''

'''Spoken Tutorial Project'''
|  | This video summarises the '''Spoken Tutorial''' Project.

Please download and watch it.

|-
|  | '''Slide Number 13'''

'''Spoken Tutorial workshops'''
|  | The '''Spoken Tutorial Project '''team:

* Conducts workshops and 
* Gives certificates.

Please write to us.

|-
|  | '''Slide Number 14'''

'''Forum for specific questions:'''
|  | Please post your timed queries in this forum.

|-
|  | '''Slide Number 15'''
'''Acknowledgment'''
|  | '''Spoken Tutorial''' Project is funded by '''MHRD, Government of India'''.

|-
|  | 
|  | This is Rani from '''IIT Bombay'''. Thank you for joining.

|-
|}